The article presents the results of research on the destruction of epoxy coatings subjected to ultraviolet radiation or 20% aqueous solutions of sodium chloride, sulfuric acid, and potassium hydroxide. X-ray and infrared spectroscopic studies documented significant oxidation of the aged coating surfaces, indicating their chemical destruction.Physical destruction of the coatings resulted in a decrease in their hardness and an increase in surface roughness. The greatest changes in surface roughness were observed in the case of exposure to a 20% aqueous solution of potassium hydroxide, for which the Ra parameter increased fortyfold after 1320 hours of aging. The aged coatings underwent cracking, and in the case of exposure to a 20% aqueous solution of sulfuric acid, coating blistering also occurred.
INFLUENCE OF AGGRESSIVE MEDIA ON DESTRUCTION OF PROTECTIVE POLYMER COATINGS
The paper presents results of investigation on surface layer destruction of epoxy coatings after the action of ultraviolet radiation or 20% aqueous solutions of sodium chloride, sulphuric acid and potassium hydroxide. Rentgenographic and infrared spectroscopic investigations proved substantial oxidation of surface layers of the aged coatings what is evidence of chemical destruction. Coating physical destruction manifested itself in lower hardness and higher surface roughness.
The highest surface roughness increase was stated in the case of ageing with 20% aqueous solution of potassium hydroxide when the value of Ra parameter increased forty times after 1320 hour ageing. The aged coatings showed cracks. In the case of the action of 20% sulphuric acid aqueous solution, coating blistering was observed. (…)
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Source: Logistyka Magazine